Marja Turunen

Biocatalytic Production of Cellobiose Containing Oligosaccharide Mixture

The production of cellobiose containing unique and novel oligosaccharide mixture from starch by cyclomaltodextrin-glucanotransferase (CGTase), using cellobiose as the acceptor sugar, is described. This is believed to be the first time such oligosaccharide production method has been published. Cellobiose containing oligosaccharides are linear molecules with one (OSG3) or several glucose units (OSG4-OSG7) adjoined to the acceptor sugar cellobiose. The effects of dry matter and enzyme concentration, the mass ratio of starch to acceptor sugar, and reaction time were studied to produce in controlled manner the oligosaccharide mixtures with a good yield. The best results were obtained in 48 h with starch of DE value 1, at 30 to 40 % total dry matter, starch/acceptor ratio of 1:1, 60 °C, and a CGTase concentration of 30 to 350 U per g of starch. Up to a 48 % yield of OSG3-5 was obtained.